I need your help with making a decision. On boxing day, I'll be able to grab either the Seagate Backup Plus 1TB or the WD Elements 1TB with carrying pouch, both for $70 + tax. Which one should I get? Reliability & portability are key.

You seem happy with WD based on your content. I have an older gen WD passport and would probably drop it for a HD + enclosure.
Honestly, if you're looking for alternative back-up options and intend on using some 3rd party software WD does not come with any software. Seagate comes with its own (for d/l too). Seagate intends on being USB, Firewire, and Thunderbolt capable (with the right adapters). I don't see that on the WD. Beyond hat, they're both decent drives.

Well I ended up getting the Seagate backup plus. Must say, it's way smaller & more importantly, lighter, than I had expected. This is a plus in my books since it fits nicely into the front sleeve of my tablet soft case. For $70, I can't complain...not that I've found anything to complain about to begin with.